opencti-mcp

search_observable

Find threat intelligence observables like IPs, domains, hashes, or emails by value or keyword, with optional type filters.

Instructions

Search for observables (raw technical artifacts: IPs, domains, hashes, emails, etc.).

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "query": "<query>"
    },
    "name": "search_observable"
  }
}

Input Schema

Name	Required	Description
`limit`	No	Max results (default: 10, max: 50)
`query`	Yes	Observable value or keyword
`observable_types`	No	Filter by types (e.g., ['IPv4-Addr', 'Domain-Name', 'StixFile'])

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.5.0Sep 6, 2026

TDQS

B3.3/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description must carry the behavioral disclosure burden. It only says 'search' without explaining matching behavior, ordering, result format, pagination, or that the operation is read-only. A search tool has limited risk, but key behavioral context is absent.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The one-sentence description is concise and front-loads the primary purpose with helpful examples. It is appropriately short for a search tool, though it could have included a usage hint without becoming verbose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema and no annotations, the description should at least indicate what the search returns or any notable result behavior. It does not. The parameter schema covers inputs, but the agent is left guessing about the output shape and whether the search is exact, fuzzy, or full-text.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all three parameters are already documented with clear descriptions and defaults. The main description adds no additional parameter semantics beyond restating the search concept, which is acceptable baseline behavior given the full schema coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb ('Search for observables') and clearly identifies the resource type with concrete examples: raw technical artifacts such as IPs, domains, hashes, and emails. This distinguishes it from sibling tools that search other entity types like threat actors, malware, or vulnerabilities.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage scope by defining observables as raw technical artifacts, but it does not explicitly state when to prefer this tool over alternatives like lookup_ioc, search_threat_intel, or get_entity. There is no mention of when not to use this tool or how it differs from exact-match lookups.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.